/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.iview2.frontend;
  
  import java.nio.file.Files;
  import java.util.Collection;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mycore.access.MCRAccessManager;
  import org.mycore.common.config.MCRConfiguration2;
  import org.mycore.datamodel.common.MCRLinkTableManager;
  import org.mycore.datamodel.niofs.MCRPath;
  import org.mycore.frontend.MCRFrontendUtil;
  import org.mycore.frontend.servlets.MCRServlet;
  import org.mycore.iview2.services.MCRIView2Tools;
  
  /**
   * Adapter that can be extended to work with different internal files systems.
   * To get the extending class invoked, one need to define a MyCoRe property, which defaults to:
   * <code>MCR.Module-iview2.MCRIView2XSLFunctionsAdapter=org.mycore.iview2.frontend.MCRIView2XSLFunctionsAdapter</code>
   * @author Thomas Scheffler (yagee)
   *
   */
  public class MCRIView2XSLFunctionsAdapter {
      private static Logger LOGGER = LogManager.getLogger(MCRIView2XSLFunctionsAdapter.class);
  
      private static final MCRLinkTableManager LINK_TABLE_MANAGER = MCRLinkTableManager.instance();
  
      public static MCRIView2XSLFunctionsAdapter getInstance() {
          return MCRConfiguration2
              .<MCRIView2XSLFunctionsAdapter>getInstanceOf(MCRIView2Tools.CONFIG_PREFIX + "MCRIView2XSLFunctionsAdapter")
              .orElseGet(MCRIView2XSLFunctionsAdapter::new);
      }
  
      public boolean hasMETSFile(String derivateID) {
          return Files.exists(MCRPath.getPath(derivateID, "/mets.xml"));
      }
  
      public String getSupportedMainFile(String derivateID) {
          return MCRIView2Tools.getSupportedMainFile(derivateID);
      }
  
      public String getOptions(String derivateID, String extensions) {
          final Collection<String> sources = LINK_TABLE_MANAGER.getSourceOf(derivateID, "derivate");
          String objectID = (sources != null && !sources.isEmpty()) ? sources.iterator().next() : "";
          StringBuilder options = new StringBuilder();
          options.append('{');
          options.append("\"derivateId\":").append('\"').append(derivateID).append("\",");
          options.append("\"objectId\":").append('\"').append(objectID).append("\",");
          options.append("\"webappBaseUri\":").append('\"').append(MCRFrontendUtil.getBaseURL()).append("\",");
          String baseUris = MCRConfiguration2.getString("MCR.Module-iview2.BaseURL").orElse("");
          if (baseUris.length() < 10) {
              baseUris = MCRServlet.getServletBaseURL() + "MCRTileServlet";
          }
          options.append("\"baseUri\":").append('\"').append(baseUris).append("\".split(\",\")");
          if (MCRAccessManager.checkPermission(derivateID, "create-pdf")) {
              options.append(",\"pdfCreatorURI\":").append('\"')
                  .append(MCRConfiguration2.getString("MCR.Module-iview2.PDFCreatorURI").orElse("")).append("\",");
              options.append("\"pdfCreatorStyle\":").append('\"')
                  .append(MCRConfiguration2.getString("MCR.Module-iview2.PDFCreatorStyle").orElse("")).append('\"');
          }
  
          if (extensions != null && !extensions.equals("")) {
              options.append(',');
              options.append(extensions);
          }
  
          options.append('}');
          LOGGER.debug(options.toString());
          return options.toString();
      }
  }